Digbijoy Labs // The Neural Blueprint — Mainframe Modernization & Exit Workbench

The Iron–Silicon Bridge: MIPS-to-Cloud Exit & COBOL COMP-3 Simulator

Official companion repository & interactive workbench for The Iron–Silicon Bridge: A Practitioner's Guide to Mainframe Modernization, COBOL, CICS, Db2, and the Agentic Exit Factory by Jay Thorne (Digbijoy Labs, 7"×10", 259 Pages, 36 Architectural Schematics).

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1. Mainframe MIPS / MLC to Agentic Cloud Exit TCO Estimator

Current Annual Mainframe Run-Rate:$0 / yr
Target Cloud Infrastructure Run-Rate:$0 / yr
Estimated Transformation Duration:0 months
One-Time Factory / Migration Cost:$0
Net 5-Year Cumulative TCO Savings:$0

2. COBOL COMP-3 (Packed Decimal) to Cloud BigDecimal Encoder/Decoder

Normalized Digit String:012540975
Sign Nibble (C=Pos, D=Neg, F=Unsigned):D (Negative)
z/OS EBCDIC COMP-3 Hex Bytes:01 25 40 97 5D
Storage Footprint (9 digits):5 bytes (Formula: ⌊N/2⌋ + 1)
PostgreSQL / Java Target Type:NUMERIC(9,2) / BigDecimal
IEEE 754 Float64 Drift Warning:NEVER USE DOUBLE/FLOAT FOR COMP-3

3. Three-Movement Book Architecture & Six-Gate Exit Readiness Checklist

Part I • Chapters 1–6

The Anatomy of Big Iron

PR/SM LPARs, Parallel Sysplex Coupling Facility XES locks, SCRT 4HRA MSU economics, COBOL COMP-3 & REDEFINES memory layouts, CICS QR/L8 Open TCBs, JES2 batch DAGs, Db2/IMS/VSAM, RACF & SMF telemetry.

Part II • Chapters 7–10

The Governed Hybrid Bridge

OIDC-to-RACF IDIDMAP & PassTicket identity propagation, multi-agent governance triads, z/OS Connect OpenAPI 3.1 & deterministic MCP tool airlocks, Kafka CDC outboxes, and IBM z17 Telum II / Spyre inference.

Part III • Chapters 11–18

The Agentic Exit Factory

SMF-weighted GraphRAG lineage, 5R portfolio triage, PDG program slicing, Z3 concolic equivalence proofs, OpenRewrite LST refactoring, EBCDIC-to-UTF-8 data liberation, Reverse-CDC Strangler Fig, and 30-day Dual-Run parity.